The present invention relates to a method and apparatus for, among other aspects, inspecting and determining the presence of defects along the edge of electronic media. For purposes of this description, the term xe2x80x9celectronic mediaxe2x80x9d refers to data storage media such as hard disks, DVDs, CD ROMs and the like, and also encompasses other media which contains or is to contain circuits and/or electronic information or data, such as semi-conductor wafers. The media may assume a variety of shapes although a specific embodiment described below has particularly applicability to electronic media in disk form.
Electronic media such as semi-conductor wafers in disk form may contain defects at the outer edge and along both side edge margins of the wafer. These defects can take various forms such as chips, cracks, scratches and marks on the surfaces near the edge of the wafer.
By determining the presence of defects, decisions can be made whether to discard the electronic media or process it in a way that avoids the defect containing portion of the media.
A need exists for an improved method and apparatus for detecting defects along the edge and edge margins of electronic media such as electronic information storage and/or circuit containing disks. The present invention is directed toward new and unobvious acts, steps and features as described below, both alone and in combination with one another. Thus, the invention is not limited to a method or apparatus which contains all of the features or addresses all of the advantages described below in connection with various embodiments of the invention.